Question

What is the ideal pressure setting for vacuum-assisted closure (VAC) therapy?

• A. -125 mm Hg
• B. 60 to 80 mm Hg
• C. 130 mm Hg
• D. 80 to 100 mm Hg

Hint:

For VAC therapy, the optimal pressure is -125 mm Hg, which maximizes wound healing while minimizing the risk of tissue injury.

Answer 1

The Correct Option is A

Step 1: Understand what VAC (negative-pressure wound) therapy does.
VAC therapy seals the wound with a foam dressing under an airtight film and connects it to a controlled suction pump. The applied sub-atmospheric (negative) pressure draws out infected exudate, decompresses interstitial oedema, mechanically deforms cells to stimulate proliferation (mechanotransduction), and improves local perfusion at the wound bed.

Step 2: Why the pressure value matters.
The therapeutic benefit is dose-dependent on the suction level. Too little suction fails to evacuate fluid or stimulate the wound; excessive suction can compromise capillary blood flow and cause tissue ischaemia. So an optimal target is needed that maximises granulation-tissue formation and microvascular flow without ischaemic injury.

Step 3: Recall the validated optimum.
Experimental and clinical work (the original Argenta and Morykwas studies) showed that peak granulation-tissue growth and peak increase in local blood flow occur at a continuous negative pressure of $-125$ mm Hg. This is the standard recommended setting for most acute and chronic wounds.

Step 4: Map to the options.
• $-125$ mm Hg → the evidence-based optimum (matches option 1).
• 60 to 80 mm Hg → too low, sub-therapeutic for standard VAC.
• 130 mm Hg → not the validated value, and pressure here is negative (sub-atmospheric), not positive.
• 80 to 100 mm Hg → below the established optimal target.

Final answer: The ideal pressure setting for VAC therapy is Option 1: $-125$ mm Hg.